About to marry, but scared I cheated.

18+ I was such a horrible boyfriend. I was friendly and flirty with other girls and I would always justify it by saying that I wasn’t cheating (which I never did). I also got super drunk during a family vacation and I don’t remember anything but I fear i may have kissed someone, even though my family has to me that I didn’t because they were with me 99% of the time. I realize however that it doesn’t take a physical act to hurt your partner. Flirting is just as bad. I don’t know why I was that way. I was always an attention seeking idiot. My guilty conscience led me to develop OCD. Now all I do is obsess over every day of my life trying to figure out if I did anything wrong so I can confess it to my partner. I wonder if I’ll ever be enough for her again. I feel so unworthy of her love. She is hurting so much and I can’t believe I caused her that pain. She tells me to let it go but I feel like she deserves to know who I was. She says she forgives me because I am no longer that person but I can fucking forgive myself. I’ve tried meditating and doing affirmations but it’s been months and I feel like I am tainted forever. I led her to believe that I was someone that I wasn’t. I told her I only had eyes for her but I still found other girls attractive and watched porn behind her back. I don’t know what to do. I don’t eat or sleep or do anything but be in my bed crying. I love her so much and I can’t believe I was such a piece of shit. I want to move forward but I don’t know how to. We’ve been together for over 5 years and I can’t believe I am just now realizing all this. I wonder if it’s too late. I’ve been an atheist for years and I’m even praying out of desperation. I hate myself

I know we can't ask for reassurance, but I need some opinions from others who understand OCD :( When my gf and I had just gone official, I had another friend who I was close with that I think had feelings for me. When I was drunk one night I called her after she left to pick me up and go to her apartment. My friend told me it was just to keep drinking because my roommate had gone to sleep in the living room, but I was so drunk I can't fully remember and feel I was making the call to fool around. Another time a few weeks later we squeezed hands while very drunk again. I've since stopped drinking and hanging out with this person, and even told my gf what happened. However I didn't go into detail about the fact that I think I might have been trying to cheat or had slightly developed feelings, just told her I felt like I had cheated by making that call at all. She took it really well but I don't feel she understands the severity, and thinks it was mostly the other girl making advances. It scares me so much because I did kiss another girl during my previous relationship yeears ago in college (my current gf doesn't know about this), so I'm scared I'm doing bad again. I feel like I need to confess and fully explain what exactly I'm worried about, and that I think the only thing that stopped me from actually cheating is that she didn't pick me up, but at this point I'm not sure if that's a compulsion or not. How do I know? Do I just confess again? I've confessed multiple times to her and it's def put a strain on things :(

My ocd is telling me I cheated on my partner 3 years ago but I don’t have any evidence at all. I keep thinking maybe I got my timing off because I was seeing someone a few months before him, but my ocd is saying that was at the same time. Any advice? Should I confess something that might have been three years ago with no evidence? How do I let go?